Population ecology and genetics of campanula genus representatives in Greek mountainous regions: the centre and edges of species distributions

• Main Authors: Tzortzaki, Anastasia Efsevia, Τζωρτζάκη, Αναστασία-Ευσεβία
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: University of Ioannina 2015
• Subjects: Πληθυσμιακή οικολογία; Γενετική πληθυσμών; Campanulaceae; Campanula lingulata; Campanula spatulata; Campanula rotundifolia; Χωρική κατανομή αφθονιας; Κέντρο και άκρα κατανομής; Ορεινοί όγκοι της Ελλάδας; Γεωμετρία fractal; Population ecology; Population genetics; Spatial distribution of abundance; Centre and edges of species distributions; Greek mountainous regions; Fractal geometry; Φυσικές Επιστήμες; Γεωεπιστήμες και Επιστήμες Περιβάλλοντος; Βιολογία; Natural Sciences; Earth and Related Environmental Sciences; Biological Sciences; Olympus
• Online Access: http://hdl.handle.net/10442/hedi/38584; https://doi.org/10.12681/eadd/38584

Patterns of spatial variation in abundance for plant species are the focus of extensive investigation. Their abundance distributions have long been associated with environmental gradients, such as moisture or elevation. According to the “abundant centre” hypothesis (ACH), species are more abundant towards the centre of their distribution along environmental gradients, where they meet optimal conditions for their survival and reproduction. As we move toward the edge, their numbers decline, since conditions are no longer favorable. The species’ “abundant centre” distribution has been the basis for many speculations on ecological and evolutionary processes — such as extinction, intra/inter-specific competition, speciation and genetic differentiation — that dictate the observed patterns of species’ occurrence and abundance across space. Populations of Campanula species (C. lingulata, C. spatulata, C. rotundifolia) where recorded along transects of approximately 74 km, across each species’ altitudinal range at the area of Mt. Olympus, Greece. Sampling took place during the summer months of 2012 and 2013. The species occurrence was mapped in various spatial resolutions ranging from 10 m to ~10 km grid squares. A total of 1,130 and 3,897 individuals were recorded for C. lingulata, 1,234 and 1,291 for C. spatulata, and 989 and 659 for C. rotundifolia, in 2012 and 2013, respectively. Most individuals were recorded at the NE and SE part of the mountain for C. lingulata and C. spatulata, while C. rotundifolia was only recorded at high elevations. An ANCOVA analysis of each species occupancy as a function of mean density across different spatial resolutions has shown significant differences in terms of the species’ “aggregation” patterns, both relative to each other, and for each year of sampling. C. rotundifolia occurrence is more restricted than those of C. lingulata and C. spatulata, while C. spatulata individuals appear significantly more aggregated relative to C. lingulata at the coarsest resolutions.C. lingulata ...